If we take the case of the robot surgeon, then the person/institution who made the decision to use the robot would presumably be responsible (e.g. in this case, the hospital). The 'obligatory supervision' in this case would mean running regular tests, getting it repaired, etc...
I think in most cases we can come up with someone who is responsible for the robot. The person who owns it will generally be the person responsible but there will be exceptions (e.g. if I borrow your robot, break the "don't attack people" software and then use it).
If, after doing all the maintenance, the robot surgeon still kills someone, then you would need to investigate. Did something go wrong with the robot? If so, is this a defect in design that the manufacturers should have thought of? If so, blame them. If not, well, no one is to blame (unless it happens with the next model... where they should have learned from the past). I suspect we'd also end up seeing recalls of robots when flaws are detected, as we do with cars occasionally.
I think in most cases we can come up with someone who is responsible for the robot. The person who owns it will generally be the person responsible but there will be exceptions (e.g. if I borrow your robot, break the "don't attack people" software and then use it).
If, after doing all the maintenance, the robot surgeon still kills someone, then you would need to investigate. Did something go wrong with the robot? If so, is this a defect in design that the manufacturers should have thought of? If so, blame them. If not, well, no one is to blame (unless it happens with the next model... where they should have learned from the past). I suspect we'd also end up seeing recalls of robots when flaws are detected, as we do with cars occasionally.